Synthetic procedures will be developed to introduce and protect functional groups in simple and complex molecules. The chemistry, in particular cyclo-additions of small ring heterocycles, will be investigated. Methods of synthesis of new heterocyclic systems will be developed and their chemistry studied. The stereochemistry, conformational analysis and mechanisms of these reactions will be investigated. Some of these compounds are of interest as potential anticancer agents. BIBLIOGRAPHIC REFERENCES: A. Hassner, D.Y. Tang, and J. Keogh, "Nucleophilic and 1,3-Additions to Triazolinediones", J. Org. Chem., 41, 2102 (1976). A. Hassner and G.E. Galle, "Ring Opening of Aziridine Phosphonates: Correlation of Structure, NMR, Spectra and Reactivity", J. Org. Chem., 41 2273 (1976).